Function 1. SUITABLE MICROPHONE Electret microphone amplifier input 3.5mm interface builtin bias, can be connected to electret microphone head microphone or 3.5 interface condenser microphone 2. POWER SUPPLY AND OPERATIONAL AMPLIFIER Adjustable gain electret microphone amplifier power supply is DC512V, using railtorail operational amplifier MC33202 3. ABOUT INTERFACE Audio preamplifier output uses 3.5mm interface, can be connected to other audio devices microphone input or au, LINE and other line input interfaces, can not be connected to headphones for listening 4. OUTPUT PORTS After the microphone and music are amplified, they can be output independently or mied. There are a total of three output ports, and the mied output port can directly drive headphones for listening 5. AMPLIFIER AND POWER SUPPLY Condenser microphone amplifier gain gain 020db adjustable, builtin 150mah capacity lithium battery, charging with mobile phone charger, one charge can be used continuously for more than 10 hoursSpecificationItem Type Electret Microphone AmplifierMaterial Aluminum AlloyPower Supply 3.7V lithium battery 150mahInput Interface 3.5mm.Package List1 Electret Microphone Amplifier1 Charging Cable